The field of this invention relates to and is concerned with jewelry, particularly necklaces, bracelets, belts or other devices and pieces of jewelry designed to encircle parts of the body, and particularly those devices used for display and ornamental purposes and made of precious metals. It is often desirable to adjust the circumference of a necklace, bracelet or belt, either for the purpose of placing the item on the body or for being removed from the body. It is further usually desirable that the adjustment of the circumference or the diameter of the device be made easily and rapidly in a simple fashion by the user, without detracting from the ornamental or decorative nature of the jewelry device. Typically, a necklace, bracelet or belt comprises an encircling chain or loop of material usually of a metal, such as gold, silver, brass or the like, and adjustment in the diameter or circumference is made by altering the position of one or the other end of the chain or loop to the loop material. It would be desirable to provide for a more rapid, economical, simple adjustment in the circumference of a device, such as a necklace or bracelet, without detracting from the ornamental or decorative nature of the device.